fr'iv  r/5' 


D»gfi&Mffe; 


Hawaii  Agricultural  Experiment  Staip 


E.  V.  WILCOX,  Special  Agent  in  C^.^^e 
PRESS    BULLETIN    IVO.   2£^ 


1^    .  /JW-  %v 

77ie  Influence  of  Mangane^^mr^ 
the  Growth  of  Pineapples.' 

By  W.   P.   Kelley, 

Chemist,    Hawaii  Experiment  Station,    United  States  Department  of 

Agriculture. 


For  a  number  of  years  the  pineapple  growers  in  the  Wahi- 
awa  district  have  observed  that  on  certain  sections  of  their  land 
pineapples  do  not  grow  well.  On  these  areas  the  young-  plants 
begin  to  grow  as  on  the  best  soils,  but  in  the  course  of  a  few- 
months  the  leaves  begin  to  s'how  a  reddish-purple  color,  which 
soon  gives  place  to  a  yellowish-white  appearance,  and  this  color 
persists  throughout  the  remaining  life  of  the  plant.  Many  of 
these  plants  never  bear  fruit;  that  which  is  produced,  however, 
is  always  of  inferior  size  and  quality.  These  areas  are  quite 
definite  and  with  the  rapid  expansion  of  the  pineapple  fields  in 
recent  years,  the  land  thus  affecting  this  crop  has  been  found  to 
be  much  greater  in  extent  than  was  formerly  thought.  All 
efforts  of  the  best  growers,  including-  the  application  of  ferti- 
lizers and  lime,  good  tillage,  drainage,  etc.,  have  failed  effectually 
to  change  the  growth  of  the  pines  on  these  lands. 


A  number  of  investigators  have  from  time  to  time  studied  the  effects 
of  manganese  on  plant  growth.  Such  studies,  however,  have  involved 
merely  the  application  of  small  amounts  of  manganese  to  soils.  The 
smallest  amount  of  manganese  found  in  our  best  pineapple  soils  is 
five  times  greater  than  the  heaviest  artificial  application  made  in  pre- 
vious experiments,  while  in  our  black  soils  the  amount  is  120  times 
greater.  Previous  experiments  with  manganese  have  been  concerned 
with  the  possible  stimulating  effect  of  minute  quantities.  In  our  pine- 
apple districts,  manganese  is  an  important  element  in  the  toil.  The 
present  bulletin  is  a  preliminary  report  on  the  first  investigation  ever 
made  of  soils  in  which  manganese  is  a  dominant  and  determining  fac- 
tor of  plant  growth. — E.  V.  Wilcox. 


In  'consideration  of  the  extent  of  such  soil,  and  its  unusual 
character,  the  Hawaii  Experiment  Station  has  undertaken  an 
extended  investigation  of  the  question.  This  work  is  still  in  pro- 
gress, but  it  is  thought  that  results  of  sufficient  importance  and 
scientific  interest  have  been  obtained  to  warrant  their  publication 
at  this  time.  This  bulletin  should,  therefore,  be  regarded  as  a 
preliminary  report,  rather  than  a  complete  discussion  of  the 
subject. 

The  pineapple  growers  have  noticed  for  several  years  that 
the  soil  which  produces  yellow  pines  in  most  instances  is  dark 
in  color,  whereas  that  producing  thrifty,  green  plants  is  usually 
red.  From  this  difference  in  color,  it  is  common  in  Hawaii  to 
speak  of  pineapple  soils  as  being  red  or  'black,  meaning  thereby 
good  or  poor  pineapple  soil;  and  it  is  in  this  sense  that  the 
terms  red  and  black  soils  are  used  in  this  paper.  In  addition 
to  this  difference  in  color,  the  black  soils  appear  to  have  a 
finer  texture  than  the  red  soils.  When  reasonably  dry  and  in 
good  tilth,  the  red  soil  usually  has  a  granular  or  "shotty"  tex- 
ture, while  the  black  soil,  under  similar  conditions,  is  reduced  to 
a  finer  state  of  division.  Upon  thoroughly  wetting,  however, 
either  of  these  types1,  may  be  crushed  between  the  fingers  to  an 
almost  impalpable  mass;  and  indeed,  to  such  a  fine  state  of 
division  that  practically  all  of  it  will  pass  through  a  one  hundred 
mes'h  sieve.  There  is,  therefore,  very  little  true  grit  in  this  sec- 
tion. It  should  be  remembered  in  this  connection  that  prac- 
tically all  soils  of  Hawaii  are  of  volcanic  origin,  and  it  seems 
that  in  this  district,  a  very  complete  disintegration  of  the  lava 
has  taken  place,  which,  in  some  places,  extends  to  a  depth  of 
thirty  feet  or  more. 

In  certain  other  pineapple  sections  of  Oahu,  particularly  near 
Pearl  City  and  Pupukea,  a  similar  condition  exists,  but  since 
there  is  a  larger  area  devoted  to  this  crop,  and  a  greater  extent 
of  black  soil  in  the  Wahiawa  district  than  in  other  sections  of 
the  Islands,  it  was  decided  to  undertake  this  investigation  at 
Wahiawa.  Accordingly,  in  September,  1908,  two  extensive  se- 
ries of  fertilizer  plot  experiments  were  begun;  one  on  red  soil, 
and  one  on  black.    There  was  a  twofold  object  in  these  experi- 


1.     The  word  "type"  is  not  used  in  this  bulletin  in  its  usual  sense, 
but  rather  for  the  sake  of  brevity. 


ments, — first,  to  determine  the  fertilizer  requirements  of  pine- 
apples in  Hawaii;  second,  to  ascertain  the  cause  of  pineapple 
yellowing-  on  the  black  soil.  This  bulletin  deals  with  the  latter 
of  these  only. 

At  the  beginning  of  these  experiments,  a  number  of  samples 
of  soil  and  sub-soil  were  taken  from  various  Darts  of  the  dis- 
trict. About  one-half  of  these  were  from  the  black  soil,  where 
the  pines  were  very  yellow;  and  one-half  from  red  soil,  produc- 
ing good  pines.  The  samples  of  soil  were  taken  to  a  depth  of 
eight  inches;  and  the  sub-soil  from  eight  inches  to  twenty  inches 
below  the  surface.  Each  of  these  samples  represents  a  compo- 
site, taken  from  not  less  than  six  different  places;  and,  there- 
fore, the  average  of  the  six  samples  of  each  type  may  be  looked 
upon  as  representing  not  less  than  thirty-six  different  places  in 
the  red  and  black  soils,  respectively.  In  the  following  table. 
is  given  the  average  water-free  composition  of  the  two  types  as 
determined  by  the  methods  of  The  Association  of  Official  Agri- 
cultural Chemists. 

TABLE  I. 


Red  Red 

Average  Composition  of                     Soils  Sub-Soil 

Insoluble  matter   42.82%  41.42% 

Potash  (K  2  O) 59  .63 

Soda    (Na  2  O) 27  .25 

Lime  (CaO)   36  .48 

Magnesia   (MgO)    39  .38 

Manganese  oxide  (Mn  3  O^  ) . . .       .37  .20 

Ferric  oxide  (Pe 2 03)    27.82  30.10 

Alumina  (AI2O3)     10.04  10.37 

Phosphorus  pentoxide   (P  205)      .08  .12 

Sulphur  trioxide  (S  O  3 ) 11  .08 

Volatile  matter 15.14  13.74 

Titanium  oxide  (TiO  2  )    2.01  2.49 

Total    100.03  100.26 

Nitrogen    (N)    . 32  .24 

Acidity   d)    1235  


Black 

Soils 

Black 

Sub-Soil 

35.26% 

37.73 

.91 

.87 

.31 

.41 

.97 

.58 

.47 

.41 

5.61 

4.90 

22.58 

22.96 

15.39 

17.20 

.27 

.16 

.17 

.06 

17.61 

13.67 

.88 

1.0S 

100.43 

100.03 

.37 

.20 

98 

1.     Calculated  to  pounds  of  CaO  per  acre  foot, 


The  growers  at  Wahiawa  often  refer  to  their  black  soils  as 
being  sour,  and  many  of  them  are  inclined  to  attribute  the  yel- 
low, dwarfed  appearance  of  the  crop  on  this  land  to  this  cause. 
Investigations,  in  other  countries  have  pointed  out  that  the 
pineapple  plant  is  very  sensitive  to  acidity ] .  But  in  view  of  the 
fact  that  the  determination  of  acidity  in  these  soils  shows  the 
presence  of  much  less  actual  acidity  in  the  black  soil  than  in  the 
red  soils,  (see  table  above),  it  seems  that,  considering  this  factor 
only,  the  black  soils  should  be  the  more  productive  of  the  two. 
Jn  fact,  every  sample  of  the  black  soil  analyzed  contained  less 
acidity  than  any  of  the  red  soils,  and  furthermore,  some  of  the 
black  soils  tested  were  found  to  be  neutral.  It,  therefore, 
seems  reasonable  that  some  cause  other  than  acidity  is  bring- 
ing about  the  unfavorable  growth.  By  reference  to  the  pre- 
vious table,  the  black  soils  are  shown  to  contain  even  more  of 
the  so-called  plant  foods  than  the  red  soil,  and  in  this  connec- 
tion, it  is  especially  noteworthy  to  point  out  that  the  black  soil 
is  well  supplied  with  nitrogen,  phosphoric  acid  and  potash. 

It  is  well  known,  however,  that  the  usual  chemical  analysis 
of  a  soil  is  not  sufficient  to  determine  its  crop  producing  power; 
that  the  chemist  often  fails  to  recognize  certain  conditions  in 
the  soil,  which  have  great  influence  on  crops;  and  further,  that 
the  usual  chemical  anlysis  fails  to  indicate  the  availability  of 
the  elements  in  the  soil;  but  without  discussing  this  subject  fur- 
ther, it  is  sufficient  at  this  time  to  say  that  the  application  of 
liberal  amounts  of  various  high  grade  fertilirers.  in  conjunction 
with  good  tillage,  drainage,  etc.,  has  not  resulted  in  overcoming 
the  yellowing  of  pines  on  this  land. 

The  plots  of  black  soil,  to  which  the  Station  applied  nitrogen, 
phosphorus,  potassium  and  calcium  in  various  forms  and 
amounts  do  not  indicate  an  effectual  remedy  for  the  yellow- 
stunted  growth  of  pines  there.  Some  of  the  same  applications 
to  red  soil,  on  the  other  hand,  are  proving  highly  satisfactory. 
What  then  is  the  cause  of  this  phenomenon? 

By  again  referring  to  the  previous  table,  one  striking  differ- 
ence in  the  composition  of  the  two  types  is  apparent,  namely,  in 
their  manganese  content.  In  order  to  bring  out  this  point  more 
forcibly,     the    following    table    is    submitted,     which    shows     the 


1.     Bui.  68,  Florida  Experiment  Station,  page  697, 


complete  analysis  of  the  soils  containing-  the  maximum,  mini- 
mum and  average  percentages  of  manganese  oxide  found  in  each 
type. 


TABLE  II. 


BLACK   SOILS 

Max.  Aver.  Min. 

Insoluble  matter 33.45%  35.26%  34. 86^ 

Potash  (K2O) 83  .91  1.06 

Soda  (Na20) 40  .31  .29 

Lime(CaO) 1.39  .97  .36 

Magnesia  (MgO) 54  .47  .40 

Manganese  oxide  (MnsO 4)      9.74  5.61  3.91 

Ferric  oxide  (Fe2  0 3) 19.65  22.58  26.39 

Alumina  (AI2O3) 15.50  15.39  14.85 

Phosphorus  pentoxide 

(P2O5) 21  .27  .18 

Sulphur  trioxide  (S  0  3)..        .16  .17  .13 

Volatile  matter 17.73  17.61  16.33 

Titanium  oxide  (Ti02)  ...        .73  .88  1.54 


RED  SOILS 

Max. 

Aver. 

Min. 

39.07% 

42.85% 

44.00 

.76 

.59 

.59 

.33 

.27 

.29 

.29 

.36 

.24 

.35 

.39 

.41 

.91 

.37 

.15 

24.98 

27  82 

27.94 

14.73 

10.04 

11.91 

.10 

.08 

.03 

.17 

.11 

.11 

17.84 

15  14 

13.94 

.23 

2.01 

.28 

99.76 

100.03 

99.89 

.34 

.32 

.29 

Total 100.33      100.43     100.30 

Nitrogen  (N) 39  .37  .30 


Since  the  above  analyses  were  made,  numerous  other  samples 
have  been  drawn  both  from  red  and  black  soil;  and  in  every 
instance,  the  samples  drawn  from  sections  where  the  pines  are 
yellow,  have  been  found  to  contain  large  amounts  of  manga- 
nese, whereas,  those  taken  from  the  red  soil,  on  which  thrifty 
pines  grow,  contain  little  of  this  element.  In  general,  the  black 
soils  contain  from  ten  to  fifty  times  as  much  mag"anese  as  the 
red  soils1. 

All  the  samples  previously  referred  to  were  drawn  from  ex- 
tremes, that  is,  either  from  sections  which  produce  very  yellow 
plants,  or  from  soils  producing  very  thrifty,  green  pines.  The 
yellow  and  green  areas  are  not  separated  by  sharp  lines  of  divi- 
sion, however,  but  rather  gradually  merge  the  one  into  the  other. 


1.  It  has  been  previously  pointed  out  that  some  Hawaiian  soils  con- 
tain large  amounts  of  manganese  (see  Press  Bulletin  No.  18,  this  Sta- 
tion); but  no  effort  has  been  made  to  correlate  yellowing  of  pine- 
apples with  the  occurrence  of  manganese  in  the  soil. 


There  is,  therefore,  an  intermediate  area  surrounding  the  yel- 
low spots  on  which  the  pines  show  the  yellowing  effect  to  a  lesser 
degree.  With  the  view  of  determining  whether  the  inaganese 
likewise  decreases  in  passing  from  the  black  soil  to  the  red, 
several  series  of  samples  from  different  places,  were  drawn  at 
regular  distances  apart,  in  passing  from  the  black  to  the  red  soil. 
From  the  analysis  of  these  samples,  a  very  close  correlation 
between  the  yellow  color  of  the  pineapples  and  the  manganese 
content  of  the  soil  was  found  to  exist. 

The  following  table  will  show  the  percentages  of  the  oxide 
of  maganese  in  black,  intermediate  and  red  soils. 


TABLE  III. 

Black. 

Intermediate. 

Red. 

Manganese  oxide  (Mn  3  0  4 ) 

5.61 

1.36 

.37 

It  seems,  therefore,  that  some  correlation  exists  between  the 
yellowing  of  pineapples  and  the  amount  of  manganese  in  the  soil, 

According  to  Leclerc1,  manganese  is  an  almost  universal  con- 
stituent of  soils,  and  it  is  often  not  determined  in  soil  analysis 
for  the  reason  that  it  is  not  usually  regarded  as  a  necessary 
element  of  plant  food,  and  is  thought  to  have  little  or  no  econo- 
mic importance  in  crop  production.  Among  all  the  analyses, 
to  which  the  author  has  had  access,  none  have  been  reported 
that  contain  more  than  a  few  tenths  of  one  per  cent  of  Mn304. 

The  solubility  of  a  substance  in  the  soil,  however,  determines 
in  a  large  measure  its  influence  on  plant  growth.  Sodium,  for 
instance,  while  not  usually  considered  as  an  essential  to  plant 
growth,  when  present  in  the  form  of  a  soluble  salt,  is  known  to 
exert  a  marked  influence  on  crops.  Wheeler  and  Hartwell2,  at 
the  Rhode  Island  Experiment  Station,  have  shown  that  solu- 
ble sodium  compounds  may  even  partially  take  the  place  of  po- 
tassium in  the  development  of  certain  plants  and  in  certain  in- 
stances sodium  may  perform  a  physiological  function  in  the  de- 
velopment of  these  plants.  The  occurrence  of  large  amounts 
of  soluble  sodium  compounds  in  the  soil,  however,  is  known  to 
be  very  detrimental  to   the  growth   of  the   plant.     As   is   well 


1.  Cited  by  Schreiber  in  Revue  Generate  Agronomique,  January,  1906. 

2.  Nineteenth  Ann.  Rept,    Of  R.  I.  Experiment  Station. 


known,  sodium  and  potassium  are  closely  related  elements  and 
have  many  properties  in  common.  Alaganese  and  iron  are  like- 
wise closely  related.  It  has  been  shown  that  when  certain  plants 
are  grown  in  culture  solutions  containing  very  small  amounts 
of  iron,  the  application  of  a  small  amount  of  soluble  manganese 
brings  about  new  vigor  and  increased  chlorophyi  production 
and  in  this  connection  the  solubility  of  the  maganese  and  iron 
in  the  black  soil  becomes  a  matter  of  interest.  The  chief  func- 
tion of  iron  in  plants  seems  to  be  connected  with  the  produc- 
tion of  chlorophyi,  and  since  the  general  appearance  of  the  yel- 
low pines  indicates  that  the  cholorphyl  has  been  affected  the 
possibility  of  some  influence  on  the  part  of  the  manganese  at 
once  suggests  itself.  In  this  connection,  Loew  and  Sawa  in 
commenting  on  the  work  of  Birner  and  Lucanus  say:  "In  re- 
gard to  the  behavior  of  plants  toward  manganese  compounds 
but  few  experiments  have  been  made  and  these  show  that  man- 
ganese cannot  replace  the  related  iron  in  regard  to  the  produc- 
tion of  chlorophyi;  and  that  the  manganous  and  manganic  phos- 
phate suspended  in  culture  solution  can  exert  an  injurious  ef- 
fect." i 

•  With  the  view  of  determining  the  solubility  of  the  manganese 
and  iron,  a  number  of  samples  of  both  red  and  black  soils  were 
extracted  with  a  one-per  cent  solution  of  citric  acid.  In  this 
determination,  200  grams  of  air-dried  soil,  were  treated  with 
2000  cc  of  one  per  cent  citric  acid  for  forty-eight  hours,  with  occa- 
sional shaking.  At  the  end  of  this  time  the  solution  was  filter- 
ed, and  the  iron  and  manganese  determined  in  the  filtrate.  The 
following  table  will  show  the  results,  expressed  in  percentages 
of  air-dried  soil  :  2 

TABLE  IV. 

Black  Soil.  Red  Soil. 

Mn304 733%  .028% 

Fe2  0.3    243  .379 

Estimating  that  an  acre  foot  of  this  soil  weighs  about  3,500,- 
000  pounds,  we  find  that  the  black  soil  contains,  on  an  average, 
about  23,755  pounds  of  citrate  soluble  mangano-manganic  oxide 


1.  Bui.  of  the  College  of  Agric.  Tokio  Imp.  Univ.,  Vol.  5,  No.  2,  p.  162. 

2.  Average  of  the  determination  in  six  samples. 


8 

per  acre  foot,  while  the  red  soil  is  found  to  contain  only  980 
pounds  in  the  same  area.  It  would,  therefore,  be  extremely 
surprising-  if  this  large  amount  of  soluble  manganese  were  with- 
out influence  in  the  soil.  It  is  sufficient  here  to  point  out  the 
relations  between  the  citrate  soluble  iron  and  manganese  in  the 
soil.  From  the  table  it  is  shown  that  these  stand  in  inverse 
proportions. 

In  the  strong  acid  digestion  of  the  black  soils,  it  was  noticed 
that  considerable  frothing  or  effervescence  developed  upon 
slightly  heating  the  same,  and  subsequently,  this  was  found  to 
be  due  to  the  escape  of  chlorine  gas.  Numerous  samples  nave 
been  treated  with  hydrochloric  acid,  and  in  every  instance,  the 
black  soils  have  been  found  to  liberate  large  quantities  of  chlor- 
ine; the  red  soils  do  not  possess  this  power. 

In  the  determination  of  volatile  combustible  matter,  it  was  also 
observed  that  after  heating  the  black  soil  just  below  redness  for 
some  hours  the  sample  still  retained  some  of  its  dark  color;  but 
upon  subsequent  stronger  heating,  further  loss  in  weight  oc- 
curred and  the  soil  took  on  a  dark  brown  color.  From  these 
facts,  it  seems  likely  that  at  least  a  part  of  the  manganese  in 
the  black  soil  exists  in  the  form  of  higher  oxides.  The  black 
color  and  the  liberation  of  chlorine  gas  suggest  the  presence  of 
manganese  dioxide,  or  of  sesquioxide  of  manganese.1  It  is,  of 
course,  likely  that  the  dark  color  is  caused  in  part,  at  least  by 
organic  matter. 

It  is  reported  that  in  some  of  these  fields  the  first  crop  of 
pines,  on  virgin  soil,  showed  but  little  yellow  color  during  the 
first  twelve  months  of  their  growth.  Later,  however,  these 
plants  became  very  yellow  and  almost  ceased  to  grow.  With 
the  continued  growth  of  pines  on  this  soil,  its  color  also  seems 
to  become  darker.  A  number  of  the  yellow  plants  were  pulled 
up  and  it  was  found  that  the  soil  adhering  to  the  larger  roots 
was  darker  in  color  than  the  general  soil.  Aso  reports  that 
wheat  grown  in  solutions  containing  a  small  amount  of  man- 
ganous  sulphate  was  found  to  contain  manganese  dioxide  ad- 
hering to  the  roots.  *2  These  facts,  together  with  the  observation 
that  the  cultivation  of  pines  on  this  soil  renders  it  less  adapted 


1.  See  "Soils"  by  Hilgard,  p.  283. 

2.  Bulletin  of  the  College  of  Agriculture,  Tokio  Imperial  University, 
Vol.  V,  No.  2,  page  183. 


to  the  crop,  indicates  that  there  is  some  change  brought  about 
in  the  soil,  by  the  crop  itself;  and  since  the  soil  of  this  entire 
section  has  arisen  from  the  disintegration  of  lava,  which,  in  its 
original  state  could  not  have  contained  either  of  the  black  oxides 
of  manganese,  it  seems  reasonable  that  in  the  growth  of  pines 
a  change  in  the  state  of  oxidation  of  the  manganese  takes  place. 

In  connection  with  the  investigation  of  the  soil,  a  study  of 
the  yellow  plants  has  also  been  undertaken.  It  was  formerly 
believed  that  the  etiolated  appearance  of  the  pines  was  caused 
by  some  pathological  or  entomological  infestation;  but  as  yet  all 
efforts  to  determine  such  infestation  have  proven  fruitless.  No 
insect  or  fungus,  which  is  known  to  produce  this  phenomenon, 
has  been  found  on  these  plants  The  root  system  of  the  yellow 
plants  was  found  to  be  dwarfed  and  much  less  extensive  than 
that  of  vigorous,  green  plants.  In  many  instances,  the  roots 
are  covered  with  a  black  coat,  and  have  but  little  indication  of 
life.  The  yellow  plants  possess  but  few  root  hairs.  The  healthy 
green  pines  on  the  contrary  have  a  very  extensive  root  system, 
•sometimes  reaching  out  to  a  distance  of  several  feet  from  the 
plant. 

Some  analyses  of  the  ash  from  both  the  green  and  yellow  plants 
have  been  made,  and  while  a  sufficiently  large  number  of  plants 
have  not  been  analyzed  to  warrant  positive  conclusions,  it  seems 
that  the  entire  metabolism  of  the  yellow  plants  has  been  dis- 
turbed. A  number  of  young  plants,  about  four  months  old,  taken 
from  both  red  and  black  soils,  and  also  an  equal  number  of 
plants  two  years  old,  were  examined.  A  composite  sample, 
made  up  of  an  equal  number  of  leaves  from  the  same  portion  of 
these  plants,  was  analyzed.  In  the  following  table  the  percen- 
tages of  manganese  oxide  in  the  ash  of  these  plants  is  given: 

TABLE  V. 

Yellow  Pines.       Yellow  Pines.       Green  Pines      Green  Pines. 
(4  months  old)    (2  years  old)     (4  months  old)     (2  years  old) 
Mns04 2.12%  1.15%  1.65%  1.68% 

In  consideration  of  the  very  large  percentage  of  easily  solu- 
ble manganese  in  this  soil  it  is  rather  surprising  that  a  higher 
percentage  of  this  element  is  not  found  in  the  pineapples  grown 
thereon,  especially,  since  it  is  generally  considered,  that,  in  the 


10 

presence  of  soluble  substances,  plants  have  the  power  of  taking 
up  these  substances  in  considerable  amounts,  it  is  interesting 
here  to  note  the  smaller  percentage  of  manganese  in  the  ash 
of  the  yellow  plants  two  years  old,  than  is  found  in  the  younger 
pines.  In  the  case  of  green  plants,  the  ash  is  found  to  contain 
about  the  same  percentage  of  manganese  in  each  of  the  two 
stages.  In  this  connection,  other  investigators  have  found  that 
many  other  plants  contain  notable  amounts  of  manganese- 
Schroder,  for  instance,  found  in  the  ash  of  the  leaves  of  the 
Norway  spruce  35-53%  Mn304.  x 

The  fact  that  the  ash  of  other  plants,  such  as  wheat,  barley, 
etc.,  grown  under  normal  conditions,  contains  not  only  a  higher 
percentage  of  nitrogen  and  potash,  but  also  more  of  these  sub- 
stances in  actual  pounds,  during  the  advanced  growing  period, 
than  at  maturity,  has  been  pointed  out  by  several  investigators. 
In  a  very  exhaustive  investigation  of  this  subject,  Wilfarth  and 
Romer2  at  the  Ducal  Experiment  Station,  have  shown  that  the 
decrease  of  the  actual  total  nitrogen  and  potash  in  wheat  and 
barley,  as  they  pass  from  the  growing  stage  into  maturity,  can 
be  explained  in  no  other  way  than  that  these  substances 
are  actually  returned  to  the  soil.  These  inevstigators  found 
that  of  the  potash  in  wheat  and  barley  at  the  time  of  flowering 
only  58.87%  of  that  in  the  former,  and  64.97%  in  the  latter 
remained  at  maturity;  and  while  it  is  true  that  potash  is  neces- 
sary to  plant  growth,  and  manganese  is  not  usually  so  consid- 
ered, the  suggested  analogy  in  the  two  cases  is  none  the  less 
interesting. 

Manganese,  when  applied  in  small  quantities,  has  been  shown 
by  several  workers  to  produce  the  effect  of  stimulation.  Nagaoka3 
at  the  Tokio  Imperial  University,  effected  an  increase  in  the 
yield  of  rice  to  the  extent  of  37%  by  the  application  of  yy  kilos 
of  manganous  sulphate  per  hectar.  At  the  Woburn  Experi- 
ment station,  the  stimulating  power  of  manganese  on  wheat  and 


1.  Cited  from  the  Bui.,  College  of  Agric,  Tokio  Imp.  Uni.,  Vol.  V, 
No.  2,  p.  161. 

2.  Researches  of  the  Ducal  Agric.  Expt.  Station,  on  The  Assimilation 
oi  the  Elements  of  Nutrition  by  Plants  During  Different  Periods  of 
Their  Growth.  Die  landwirtschschaftlichen,  Versuchsstationen,  Vol.  63, 
1905. 

?>.     Bui.,  College  of  Agric,  Tokio  Imp.  University,  Vol.  VII,  No.  1. 


II 

other  crops  has  also  been  determined;  and  other  investigators 
have  found  that  small  amounts  of  various  manganese  com- 
pounds produce  the  same  effect.  The  fact,  however,  that  small 
quantities  of  a  substance  exert  a  stimulating  effect  does  not 
necessarily  imply  that  larger  quantities  would  be  beneficial.  In 
the  animal  organism,  for  instance,  a  small  amount  of  alcohol  is 
known  to  produce  the  effect  of  stimulation,  whereas  larger 
amounts  have  a  depressing  effect.  The  same  may  be  said  of 
ether  and  chloroform.  With  plants,  there  are  several  well  known 
examples  of  the  same  condition.  Katayama  ]  and  others  have 
shown  that  ferrous  sulphate  in  small  quantities  produces  a  sti- 
mulation of  certain  plants;  and  whether  or  not  this  is  brought 
about  by  bringing  into  solution  some  of  the  dormant  bases  of 
the  soil,  larger  quantities  of  the  same  substance  are  often  referred 
to  as  actually  poisonous  to  the  plants.2  Sutherst3  has  shown  that 
the  application  of  small  amounts  of  various  manganese  com- 
pounds, including  the  dioxide,  has  a  stimulating  effect  on  maize, 
but  he  points  to  the  work  of  Salamone  as  indicating  that  larger 
amounts  of  these  substances  are  detrimental. 

The  question  of  how  these  substances  produce  stimulation,  in 
small  quantities,  and  a  depressing  effect,  when  present  in  large 
quantities,  is  not  thoroughly  understood;  but  that  such  i^s  the 
case,  is  generally  accepted.  Aso  4  for  instance,  has  shown  that 
a  given  amount  of  manganese  may  produce  stimulation  of  rice, 
whereas  the  same  amount  of  this  element,  when  applied  to 
wheat  and  barley,  may,  under  certain  conditions,  result  in  de- 
creased vigor  and  the  development  of  a  yellow  color  in  the  plant. 
This  author  has  further  pointed  out  that  the  depressing  effect 
of  such  applications  of  manganese  is  usually  more  marked  in 
cold  weather  than  in  warm;  and  with  the  return  of  warm  wea- 
ther, in  some  instances,  these  plants  were  able  to  entirely  over- 
come the  stunted  growth  and  yellow  color. 


1.  Bui.  College  of  Agric,  Tokio  Imperial  University,  Vol.  VII,  No.  I. 

2.  "Agriculture"  by  Storer,  Vol.  I,  p.  216. 

3.  "Manganese  Compounds  as  Fertilizers  for  Maize,"  The  Transvaal 
Agric.  Journal.     Vol.  VI,  No.  23. 

4.  Bui.  College  of  Agric,  Tokio  Imperial  University,  Vol.  V,  No.  2, 
pp.  177-185. 


12 

We  find  a  parallel  condition  at  Wahiawa,  where  the  pine- 
apples on  soils  which  contain  an  intermediate  quantity  of  man- 
ganese, have  been  repeatedly  observed  to  become  decidedly  yel- 
low during  the  winter  months;  but  such  plants  sometimes  en- 
tirely overcome  this  condition  with  the  return  of  warm  weather. 
It  should  be  mentioned  in  this  connection  that  sugar-cane  grows 
exceedingly  well  on  these  manganese  soils,  where  the  pineapples 
refuse  to  grow. 

Bertrand  l  some  years  ago,  found  that  the  ash  of  oxidizing 
enzymes  contains  considerable  amounts  of  manganese,  and  that 
the  addition  of  soluble  manganese  salts  to  the  oxidase  greatly 
accelerated  their  oxygen  carrying  power.  Woods  2  has  shown 
that  the  yellow  spots,  which  sometimes  occur  on  leaves  of  cer- 
tain plants,  have  a  greater  oxidizing  power  than  the  green  parts 
of  the  same  plant.  In  seeking  an  explanation  of  the  yellow 
color  produced  by  the  application  of  manganese  sulphate  to  bar- 
ley, Loew  and  Sawa  found  that  such  plants  are  more  vigorous 
oxidizing  agents  than  those  not  treated  with  manganese.  Sum- 
marizing these  effects,  they  say:  "Manganese  exerts,  in  mod- 
erate quantity,  an  injurious  action  on  plants,  consisting  in  the 
bleaching  out  of  the  chlorophyl.  The  juices  of  such  plants  show 
more  .intense  reactions  for  oxidase  and  peroxidase  than  the 
healthy  control  plants.  Manganese  exerts  further  a  promoting 
effect  on  the  development,  still  observable  in  high  dilution,  while 
the  injurious  effects  disappear  under  this  condition.  It  is  prob- 
ably that  soils  of  great  natural  fertility  contain  manganese  in 
an  easily  absorbable  condition,  and  this  forms  one  of  the  char- 
acteristics of  such  soils."  8 

With  the  view  of  ascertaining  whether  yellow  pineapple  plants 
are  more  vigorous  oxidizing  agents  than  the  green  plants,  a 
small  portion  of  both  yellow  and  green  leaves  were  macerated 
with  crushed  glass,  allowed  to  stand  about  an  hour,  and  the  ex- 


1.  Compt.  rend.  Vol.  124,  Page  1032. 

2.  Abstracted  in  E.  S.  R.  Vol.  XII,  p.  216. 

3.  Bulletin,  College  of  Agriculture,  Tokio  Imperial  University,  Vol. 
V,  No.   2,  p.  172. 


13 

tract  was  tested  for  oxidase,  using  the  guiacum  and  aloin  tests; 
the  following  table  will  show  the  results : 

TABLE  VI. 

Guiacum  Aloln. 

Yellow  leaves  Deep  blue.  Rose  red. 

Green   leaves  Pale  blue.  Faint  red. 

It  is  thus  shown  that  the  plants  grown  on  the  soil  containing 
high  percentages  of  manganese,  contain  a  more  active  oxidase 
than  plants  from  soil  containing  little  manganese;  and  whether 
the  increased  activity  of  the  oxidase  in  the  yellow  plants  brings 
about  their  etiolated  appearance,  by  the  actual  oxidation  of  the 
chlorophyl,  or  for  other  reasons,  cannot  be  positively  stated  at 
this  time.  An  examination  under  the  high  pGwer  miscroscope 
of  the  cross-section  of  the  yellow  leaves,  shows,  however,  that 
for  the  most  part  the  chlorophyl  bodies  have  been  entirely  de- 
stroyed. Further  investigation  it  is  hoped  will  throw  more  light 
on  this  subject. 

SUMMARY  AND  CONCLUSIONS. 

i.  Some  of  the  pineapple  soils  of  Hawaii  contain  black  spots 
on  which  pineapples  do  not  grow  successfully. 

2.  The  application  of  fertilizers  and  lime  in  conjunction  with 
good  tillage  and  drainage,  has  not  resulted  in  effectually  overcom- 
ing the  yellow  appearance  of  the  pines  on  black  soil. 

3.  The  black  soils  contain  less  acidity  than  the  red  soils. 

4.  There  is  but  one  important  difference  in  the  chemical 
composition  of  these  soils,  viz.,  in  regard  to  the  manganese 
content.  The  black  soils  contains  many  times  as  much  man- 
ganese as  the  red  soil. 

5.  The  black  color  of  these  areas  may  in  part  be  attributed 
to  the  presence  of  higher  oxides  of  manganese. 

6  There  is  a  close  correlation  between  the  degree  of  yellow- 
ing of  the  pines  and  the  percentage  of  manganese  in  the  soil. 


14 

7-  Yellow  pines  from  soils  containing  a  high  percentage  of 
manganese  are  more  active  oxidizing  agents  than  green  plants 
from  red  soil. 

8.  The  yellow  pines  have  a  poor  root  system  and  contain  but 
little  chlorophyl. 

9.  As  yet  no  positive  remedy  for  this  condition  has  been 
worked  out.  It  seems  wise  to  try  other  crops  on  the  black  soil, 
especially  since  sugar-cane  grows  well  on  the  black  soil. 

This  investigation  is  being  continued  along  the  lines  suggest- 
ed in  the  body  of  this  bulletin.  Acknowledgments  are  due  Miss 
Alice  R.  Thompson,  Assistant  chemist,  for  assistance  in  this 
work.  A  large  part  of  the  analytical  work  was  done  by  her, 
and  many  valuable  suggestions  were  offered  from  time  to  time. 
Also  to  Doctor  E.  V.  Wilcox  for  the  microscopic  examination 
of  these  plants,  and  for  many  very  valuable  suggestions.  Thanks 
are  also  due  the  pineapple  growers  at  Wahiawa  for  cooperation 
in  this  work. 


UNIVERSITY  OF  FLORIDA 


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